Field of the Invention
The present invention relates to a control method of an electrical thermostat and the system thereof that changes a passage of a coolant depending on the temperature of the coolant and actively controls the coolant temperature to prevent overheating thereof.
Description of Related Art
A thermostat for a vehicle is disposed between an engine and a radiator, is automatically opened/closed by the temperature variation of coolant to adjust the flow rate of the coolant, and therefore the temperature of the coolant is controlled in a predetermined range.
A mechanical thermostat expands wax depending on the temperature of the coolant, and the expanding force of the wax makes a piston move the valve of the thermostat.
The mechanical thermostat is operated in a predetermined opening/closing temperature of the coolant to open/close the valve only in a predetermined temperature condition, and therefore the mechanical thermostat does not actively move against changes of the driving circumstances of the vehicle.
Accordingly, an electrical thermostat has been introduced to complements the drawback of the mechanical thermostat, and the electrical thermostat is operated to sustain the coolant temperature in an optimized range.
The electrical thermostat actively controls the coolant temperature of the engine according to the driving circumstances such as the load level of the vehicle to sustain the optimized coolant temperature, and the electrical thermostat can improve fuel consumption efficiency and reduce exhaust gas.
A drive portion that is a temperature sensitive type and is electrically controlled has been applied to open or close the valve of a thermostat, and the drive portion includes wax, semi-fluid, a rubber piston, a back-up plate, and a main piston.
Here, a coolant temperature is low before an engine is started, and therefore fuel consumption and harmful exhaust gas can be increased by the low temperature coolant. Accordingly, the arts for quickly raising the coolant temperature have been researched.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.